John p



J. P. JAMISON.

DRAWING INSTRUMENT.

No. 32,566. Patented June 18,1861.

JOI-IN I. JAAIISOhhOF NEW YORK, N. Y.

DRAWING INSTRUMENT.

Specification of Letters Patent No.` 32,566, dated Julie 18, 1861.

To all whom t may concern.

'Be it known that I, Jol-IN I). JAMIsoN, of New York, in the county and State of New York, haveinvented, made, and applied to use a new and `Improved Instrument for Drawing and Ruling; and I do declare the following to be a full, clear, and correct description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, in which- Figure I. is a front view of my improved drawing instrument; Fig. 2. a view of the slotted bar A3; Fig. 3. a view of the pointer of the indicating apparatus; Fig. IV. a view of the circular plate of the same; Fig. V. a View of the tube D with the case A attached; Fig'. VI. a view of nut for upon the tube'D. Y

In the drawings like parts of the invention are designated by the same letters of reference.

.The nature of my invention cons iu the construction and operation of an instrument for drawing and ruling, to be used by draftsmen, architects, engineers and others, by the use of which, the ordinary square, straight edge divides, oblique and radiating rules may be dispensed with.

To enable those skilled in the arts to make and use my invention I will proceed to speak of the construction and operation of the same.

0onsruotz'ova`A shows a beam supported by the uprights B B placed at each end of the same. Thisbeam A may be made of wood ormetal, of any desired length and may be divided 'into a scale of inches and parts of inches, by dots or lines stamped or engraved atthe proper distances from each other upon it.

Yshows a sliding piece, formed of metal, which moves freely upon the beam A and is held in any required position by means of a set screw passed through it and bearing against the beam A. This sliding piece Y has cast directly upon, or attached in any desired manner to, its upper surface, the circular plate of metal C, of the indicating apparatus, having' stamped or engraved upon it, the degrees of the circle, while upon the back of the sliding piece Y is cast or attached the hollow metallic tube D which tube D projects through and above the circular plate C.

E shows the pointer of the indicating apparatus, formed like the hand of a clock, aud

. having its bearing coniining pointer tted snugly upon the tube D to which it held by means of the nut c, in such a mann that it may be readily revolved', while it held firmly in any desired position by meal of the screwpoint Z) attached t-o one end 1 it. I would here remark that this pointer governs and determines the position occ pied at any time by the pencil holder hereinafter described. Through this` tube passes or is introduced the center point l directly upon the pape tracing muslin or other material employe G is a case, attached to the lower portie of the tube D, in which is inserted the bea] A2 divided in a similar manner as the bea] A into inches and parts of inches: this bea] A2 is adjustable and may beretained in an desired position by the set screw o.

I-I shows a foot with a roller d and with hollow projecting head o, which is place upon the beam A2 at either end and aid materially inthe smooth and ready passag of the same, over the paper, tracing musli or other material employe-d.

I shows a tubular slide,` placed upon th beam A2, upon the back end of which is ca.c or attached the pencil holder J, intended t receive the pencil, pen. or point.l To lth lower end of this pencil holder J is attache( by means of the set screw g, the slotted bean A3, divided into a scale of inches and part thereof, engraved thereon.

L shows a slide provided with a penci holder M, in which is inserted a pencil, pei or point and which pencil holder M is move( to and fro upon the beam A2.

Operatio1i.-'l`he instrument being thu: constructed may be attached to a drawing board at any particular part of the same, b5 pins, and the paper, tracing muslin or othei material employed is placed and held upor the drawing board in the ordinary manner In order to form straight lilies by the instrument the pointer E is revolved until it reaches the Zero or beginning point before the circular plate C, by which movement, the beam A2 is placed at right angles to the beam A. The sliding. piece Yis then moved to the right or left upon the beam A and t-he pencil, pen or point, inserted and held in the pencil holder J, marks upon the paper, tracing muslin or other material employed, as it passes over thesame, a straight line, corresponding in length to the distance in inches and parts of the same traversed by the sliding piece Y upon the beam A. If desired to form a second horizontal ork parallel line, or any number of parallel lines, at a given distance from each other or from the lirst line marked upon the paper, tracing muslin or other material employed, the slide I is moved the desired distance in inches and parts of the same upon the beam A2 and the operation first described is repeated. When it is desired to mark perpendicular lines, the operation is performed by retaining the parts first named in the same position and moving the slide I with the pencil holder J to and fro upon the beam A2: the length of the line thus 'marked is determined by the distance in inches and parts of in ches,

traversed by the slide I upon the beam A2.,

When desired to form a second perpendicular yline or any number of them at a given distance from each other or from the vlirst line marked, the sliding piece Y is moved the desired distance upon the beam A and the operation first described of the slide I isrepeated. In the formation of oblique A lines at an oiven ano'le,A the Jointer E of the indicating apparatus is placed opposite the desired degree upon the circular plate C:

.by this movement of the pointer E upon the v circular plate C, the beam A2 is brought into line drawn.

Aa corresponding angle and the line is marked upon the paper, tracing muslin or other material employed, by moving the slide I to Which is attached the pencil holder J, to and fro upon the beam A2, the length of the lines marked, being determined by the number of inches and parts of inches traversed over by the slide I upon the beam A2, While the distance between them may be governed by moving the sliding piece Y upon the beam A. In order to4 form radiating lines, the sliding piece Y is placed at the center of the beam A and held in position by a set screw. rIhe pointer E is then revolved until it points to the zero or beginning point, upon the circular plate of metal C, the beam A2 being thus placed at right angles to the beam A. The first line is th en marked upon the paper, tracing muslin or other material employed, by moving the slide I upon the beam A2 the distance desired for the length of the line and the operation is repeated, the pointer E being revolved until it indicates upon the circular plate C the exact degree of Obliquity desired to give to the In forming larger circles, the sliding piece Y is placed in the center of the beam A and retained in this position by a set screw. The center point F thus forms a center, around which, the beam A2 to Which is attached the pencil h older J by slide I, is revolved and the pencil, pen or point, marks upon the paper, tracing muslin or other material employed, a circle, the diameter of Which may be determined by moving the slide I one half the required diameter in inches and parts of the saine from the center point F upon the beam A2. To form any part of a circle, the parts should be retained in the same position and the beam A2 to which is attached the pencil holder J is revolved until the pointer E indicates upon the circular plate C the requisite number of degrees. In making circles requiring a different center, I employ the beam A3 constructed as described, the pencil, pen or point placed and held in the pencil. holder ,J forming a center, around which is revolved the pencil, pen or point placed and held in the holder M', forming a circle, the diameter of which may be determined by moving the slide I, one half the required diameter in inches and parts of the same upon the slotted beam A2.

The position of the instrument in forming circles may be varied at pleasure, by

moving the sliding piece Y upon the beam A operated in the manner described for the purpose shown.

3. The pencil holder M operating as described in combination With the pencil holder J, slide I, beam A2 and tube D, arranged and operated as shown for the purpose set forth. fl. rl`he point F inserted in the tube D in combination With the slide I and pencil holder J, arranged and operated as described forthe purpose set forth.

JOIIN P. JAMISON. In presence of- C. C. EGBERT, JosErI-r GUTMAN, J r. 

